Which of the following compounds contains polar covalent bonds?

• A. NaCl
• B. H_2O
• C. F_2
• D. O_2

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the concept of bond polarity. A polar covalent bond occurs when two atoms share electrons unequally due to a difference in electronegativity between them.
2. Step 2: Analyze each compound's bonding type and electronegativity difference. NaCl is an ionic compound formed between a metal (Na) and a nonmetal (Cl), so it does not contain covalent bonds but ionic bonds.
3. Step 3: For F_2 and O_2, both are diatomic molecules consisting of two identical atoms. Since the atoms are the same, the electronegativity difference is zero, resulting in nonpolar covalent bonds.
4. Step 4: For H_2O, the molecule consists of hydrogen and oxygen atoms. Oxygen is more electronegative than hydrogen, so the electrons are shared unequally, creating polar covalent bonds.
5. Step 5: Conclude that among the given options, only H_2O contains polar covalent bonds due to the difference in electronegativity between hydrogen and oxygen.